ConditionGeneral Motors has decided that a defect, which relates to motor vehicle safety, exists in certain 2004 and 2005 model year Cadillac XLR vehicles, and 2005 model year Chevrolet Corvette vehicles. The rear brake lines may contact other components or be affected by heat from them.

If contact occurs, the driver may hear a rattle noise. Over time, the contact could cause brake line wear-through resulting in a slow loss of brake fluid, which would appear as fluid spotting under the vehicle. On XLR vehicles, this could also create a visible puff of smoke when the brakes are applied. If enough fluid is lost, the performance of the rear brakes will be reduced, there would be an increase in brake pedal effort in order to achieve the desired braking, and the brake system warning light may illuminate on the instrument panel.

If the brake line on XLR vehicles is affected by heat, the fluid in the brake line could boil. The performance of the rear brakes will be reduced and there would be an increase in brake pedal effort in order to achieve the desired braking.

If this were to occur when stopping distance is limited, a crash could occur.

Correction Dealers are to inspect, and reposition or secure if necessary, the rear brake lines to ensure that there is adequate clearance from other underbody components. On some vehicles, a machining tab on the rear differential housing may need to be removed to provide adequate clearance. The rear brake lines are to also be inspected and, if damaged, repaired.

2005 Chevrolet Corvette VIN breakpoints: 55100321-55101325

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.